Ok, first off, I goofed. There are two passive GTX 750 cards. Palit Kalm X and Zotac Zone. Here's a review at Hardwareluxx.
Amazon has the Zotac card for $120.
Now that I've gotten you to show more of your cards, here's some comments.
- A passive gfx card needs some case airflow in order to keep the temps down. Not sure your Rosewill case with its two tiny fans will do the job.
- Yep, that's an old CPU and mobo. (Ok, I just replaced my E8400 a year ago - I know the feeling).
- Upside to the GTX 750 - it's much faster than your current card, uses much less power, it'll be silent. Downside: if you are INTO gaming, and plan to play at 1080p, then the GTX 750 is as low as I'd recommend. You'd have to turn down the image quality to get decent framerates...depending on the game....and then your 2.4GHz Q6600 will be the limiter. Then, when you upgrade the CPU to a current gen, the 1GB GTX 750 will be the limiter.
Cheapest solution is to try and remove the fan shroud and the single fan. Strap a pair of $10ish case fans to the cooler and be done. Sound easy, but could be a pita. Need to measure the heatsink cooler to see what could fit. Need to look at the fan connector on the gfx card for size/number of wires(2? 3? 4?). Probably end up using a Zalman Fan Mate 2
, a y- connector
, and a fan connector to molex cable that should have come with your PSU. Plus cable ties and something to isolate the fans from the heatsink (adhesive furniture pads or the fuzzy half of adhesive backed velcro.